PRELIMINARY STUDY OF THE ANTIMICROBIAL EFFECT OF WATERMELON BARK (ENDOCARP OR RIND ON S. THPHI, E. COLI AND S. AUREUS

ABSTRACTIn a research conducted to ascertain the antimicrobial activity of watermelon (Citrullus lanatus) bark on organisms such as Escherichia coli, Slamonella typhi and Staphylococcus aureus using the ethanol and auqous extracts of the watermelon bark applying agar-well and pour-plate sensitivity technique.   It was observed that the ethanoic extract (dry) of watermelon bark on agar well showed a high inhibitory activity of Staphylococcus aureus and Escherichia coli and shows a moderate inhibition on Salmonella.  While on pour-plate method the aqueous extract (dry) showed a high inhibitory act on Escherichia coli and Staphylococcus aureus and none on Salmonella.Keywords:  Watermelon (Citrullus lanatus) bark, extract, antimicrobial activities, E.coli, S.typhi, S. aureus.
TABLE OF CONTENTSTitle PageApproval PageDedicationAcknowledgement Table of ContentList of TablesAbstract 
CHAPTER ONEIntroduction Objective 
CHAPTER TWOLiterature ReviewPlant TaxonomyThe plant descriptionHealth benefits of watermelonUse of watermelonVarieties Chemical constituentStaphylococcus Staphylococcus aureusEschericha Escherichia coliSalomella 
CHAPTER THREEMATERIALS AND METHODSMaterials Method Sterilization of WaterTest Organism Inoculation of the Test Organism Preparation of MediaNutrient BrothPreparation of Extract Antimicrobial susceptibility test
CHAPTER FOURRESULT OF ANTI MICROBIAL ACTIVITIESResult of the Activities of the Extract againstStaphylococcus aureus using pour plate and agar-well methodResult of the activities of the extracts againstEscherichia coli using pour plate and agar-well methodResult of the activities of the extracts against Salmonella typhi using pour plate and agar-well methodDISCUSSION
CHAPTER FIVECONCLUSIONRECOMMENDATIONREFRENCES

LIST OF TABLES AND FIGURESTABLES 1. Result of Antimicrobial activity of the extracts against Salmonella typhi2. Result of Antimicrobial activity of the extracts against Escherichia coli.3. Result of Antimicrobial activity of the extracts against Staphylococcus aureus
FIGURES1. Structure of Beta Carotene2. Strcuture of Arginine 3. Structure of Citrulline4. Structure of Lycopene5. Agar well method on S. typhi6. Pour plate method on S. typhi   
INTRODUCTION Citrullus lanatus is among the genera in the family Cucurbitanceae.  Its plant is slender, sprawling, slightly hairy monoecius annual plant.  The stems or runners may extend 0.3 to 10m.  in its natural environment, it grows in grassland or bushland, often along watercourses at altitude of 50 to 1400m.  it grows in well-drained soil and can withstand drought better than other melons.  It is widely distributed in Africa and Asia but originate from Southern Africa. Citrullus lanatus fruit is popularly consumed in different part of the world.  The juice quenches the thirst of water.  It concentrates powerful antioxidants such as lycopene and carotenoid which travels through the body neutralizing free radicals that can lead to stroke or heart attacks, the juice can also be probioticated using different strains of lactobacilli against Salmonella typhimurium (Fazeli et al., 2007).  The rind can be used in jam, jelly, pickle and wine production.  The seed can be used in oil production (Taiwo et al., 2008).  The leaf extract of Citrullus lanatus with different solvent viz, benzene, petroleum either and methanol were tested and have shown larvicidal, ovicidal, repellent and insect growth regulatory activities against Anophele stephensi (Diptera culicidea) and malaria vectors (Mullai et al., 2008.  The fresh fruit contains Cucurbitacins, common secondary plant compound of the cucurbitacea, are feeding stimulants for several species of beetles in the corn rootworm complex (DeMilo et al., 2000).  Cucurbitacin can also be added to bait containing an insecticide thereby reducing the levels of other insecticides treatment needed to control pests. Staphylococcus aureus are spherical cocci about 0.8 – 1.0µm in diameter.  They are characteristically in grape-like clusters.  They are non motile, non sporing and with the exception of rare strains are non capsulated.  They are gram-positive aerobes and facultative anaerobes.  Staphylococcus aureus is an opportunistic pathogen in that it causes infection most commonly in sights of lowered host resistance (Arora, 2003).      Escherichia coli is a gram negative bacterium, it is non capsulated, aerobe and facultative anaerobe commonly found in the lower intestine of warm blooded organisms.  It measures 1 - 3µm x 0.4 – 0.7µm in size.  The harmless strain are part of the normal flora of the gut and can benefit their host by producing Vit. K2 or preventing the establishment of pathogenic bacteria within the intestine (Brooks et al., 2007). Salmonella – it consist of facultative anaerobic gram-negative, non-sporing, non acid fast, non capsulated bacilli that parasites the intestines of a large number of vertebrate specie.  Most strains are non motile by means of peritrichous flagella.  It causes diease such as enteric-fever, speticaemia and food poisoning (Dampster 1992). This present study examines the antimicrobial activities of the extracts of the bark of Citrullus lanatus against Escherichia Coli, Staphylococcus aureus and Salmonella typhi.